Process of producing printing plates



Patented Oct. 29,1929- warren A STATES PATENT OFFICE ROY V. GRAVES, OFMINNEAPOLIS, MINNESOTA, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TOTHE GRAVES PROCESS, INC., 0]? MINNEAPOLIS, MINNESOTA, A

CORPORATION OF DELAWARE IROCESS OF PRODUCING PRINTING- PLATES NoDrawing. Application filed June 10, 1926, Serial No.115,129 RenewedDecember 3, 1928.

My inventionhas for its object to provide a new and economical processfor the production of printing plates having unshrunk type in highrelief capable of use for printing purposes, in substitution for handset type, machine set type, machine cast and settype, or'machine castand set slygs.

The said process, in its preferred form. is hereinafter described andpointed out in the claims. In carrying out my invention, I first producea translucent master sheet containmg the desired composition in opaqueimpressions. A good quality of white bond paper is suitable for thepurpose; and one way of getting the opaque impressions of thecomposition is by writing out the composition withthe use of a suitabletypewriter on the face of the sheet of bond paper with a carbon faced tothe back of the bond paper, which will have the effect of producing thecomposition right sideup on the face of the sheet of bond paper andreversed on the back of said sheet of bond paper or in print andcounterprint; and, when this has been done,

one suitable form of translucent master sheet will be available.

It is a matter of convenience also to produce, at the sametime, on thetypewriting machine, a proof of the composition. which can be readilydone by placing an additional carbon against the face of an additionalcopy a sheet of paper behind the first carbon above .noted.

The Hammond, multiplex typewriting machine is well adapted for use inproducing this master sheet.

The special reason for producing the composition right side up on theface of the master sheet and reversed on the back of said.

machine with the proper kind of properly inked ribbon should beemployed. The essen tial point is, that the impressions of thecomposition must be opaque.

The next or second step is to rovide a suitable metallic plate havingits ace sensitized with a material which is normally soluble in waterbut can be made insoluble in water by exposure to light. An ordinaryzinc or cop per plate having its face so sensitized may be cannot passthrough theportions of the master sheet occupied by the opaqueimpressions, and; hence, the sensitized material on the surfaces of theplate covered by said opaque impressions remains soluble in water. Whena negative plate is desired, suitable for printing in relief right sideup, the said master sheet must be applied to said plate with its facedownward,

The next or fourth step consists in remov-. ing the sensitizing materialfrom the surfaces of said plate which had been covered by the opaqueimpressions of the master 4 sheet, which can readily be done by washingthe plate in water, thereby leaving said surfaces exposed.

Then the next or fifth step consists in covering the said exposedsurfaces of said plate with a material which will resist the chemicalsused respectively in the sixth and seventh steps. Ordinary printers inkwill serve the purpose and it can be readily applied with a suitableinking-roller. Y

Then the next or sixth step consists in removing the sensitized materialfrom the sur faces of said plate which had not been covered by theopaque impressions of the master sheet. which can readily be done byswabbing the plate with a dilute solution of hydrochloric acid.

those surfaces of said plate which had not been :covered by the opaqueimpressions of the master sheet, thereby leaving the surfaces of saidplate which had been covered by the opaque impressions of the. mastersheet stand ing high and distinct in relief, and thus affording anunshrunk negative plate available for printing right side up.

For this last, or etching step of the process, I preferably employ theetching machine and process disclosed in U. S. Patent 1,422,977, grantedof date January 23rd, 1923, to Edward G. Schwuchow and George F.Johnstone, wherein an alkaline solution is em: ployed as the electrolyteof the bath. I prefer to employ the process disclosed in said U. S.patent as I have found it to be extremely eflicient for the purpose. Itcompletely disposes of the metal etched away and does no injury to theintended printing surfaces. It is possible, however, that Imight employother suitable forms of electrolytic or acid baths; and, hence, I do.not limit myself to the use of this particular process disclosed in saidpatent for my etching step.

When the plate comes from the last step of the process above stated, itis obvious that it is in-fiat form and that it could be used in saidflat form on some kinds of printing presses; but, for newspaper work,said plate would be curved into half cylinder form, by

the suitableapplication of pressure thereto, and then be mated byanother similar plate for the formation of a complete cylinder adaptedto be applied and used on the cylinders of the ordinary newspaperprinting press, in the same way as the half cylinder plates cast in theusual way from matrix molds. Of course, it will be understood that theplate as it comes from the last step of the above named process willalso have to be trimmed, for gettingtheneeded bevelled edges and soforth. Special attention is called to the fact that, inasmuch as all thesteps incidental to stereotyping'have been elimin-- ated, my plate andtype are unshrunk. The

type therefore corresponds precisely to the composition in all respectsincluding face dimensions.

In the foregoing statement, the word" composition has been used andisherein afterused in the claims, in a broad sense to cover and includenbt only reading mat-' ter, but impressions made from 'cuts, halftones,or electro-plates, for use in association with the reading matter orindependently of the reading matter. As typewriting machines are nowmade, however, so far as I know, I cannot getdirectly therefrom a mastersheet for out impressions. Hence, I get such a master sheet from a woodcut, a half-tone or an;electro-plate made in the writer. When the cutmaster sheet has thus been obtained, it can be associated with thereading master sheet, throughout all the steps of the process abovestated, and the final result will be a plate adapted to print thereading matter and the cut matter in association with each other. Forexample, a single sheet of bond paper of the proper width may be used toreceive both the reading impressions and .the cut matter impressions,side by side, in separate columns, or with the cutmatter interposedbetween paragraphs of the reading matter of the same columns. Ordinarilythis master sheet suitable for the double purpose above named would bemost conveniently secured by applying the wood cuts, halftones orelectro-plates to the sheet of bond paper first, at the portionsthereofdesired, and then writing in on said sheet the desired reading matter onthe typewriting machine.

Of course, it will be understood that the reading composition of themaster sheets produced on the ordinary typewriting machine would not, ofnecessity, be perfectly justified. A rough justification could besecured by an advance alarm, on the typewriting machine, which wouldcall the operators attention, at the proper time, to the remaining linespace available, so he could spread or crowd the last words of the lineof the composition. If, however, perfect justification should bedesirable, it could be secured, by making the original composition ofthe reading matter on a typewriting machine having a line-space counter,which would show the shortage or excess of space needing distribution toget justification, and, then, making a second copy from this originalmeasured copy, on the typewriting machine, in which second copy thespace would be so distributed between the words of the line as requiredto secure justification.

It will be understood that some of the details of my processabovedescribed can be changed or varied without departing from thespirit of the invention herein disclosed and pointed out in the claims.For example, while the specific meansspecified for carrying into effectthe fourth, fifth, sixth, and seventh steps of my process are the bestvknown to. me' for the purpose, it is possible that other s ecificallydifferent means might be employed:

It is obvious that the second, third, fourth, fifth and sixth stepsabove specified, taken collectively, constitute a means of transferringthe composition from the. translucent master sheet to the metallicprinting plate.

What is claimed is:

1. The process of producing printing plates having type in high relief,which process includes the following steps, to-wit: (a) producing amaster sheet having typewritten thereon the desired composition inopaque printed and counterprinted impressions, the remaining portions ofsaid sheet being translucent; (b) transferring the composition of themaster sheet to a metallic printing plate; (0) etching off from the faceof said metallic plate all the face surfaces thereof not correspondingto said composition of the master sheet.

2. The process of producing printing plates having type in high relief,which process includes the following steps, to-Wit: (a) producing atranslucent master sheet containing the desired composition intypewritten opaque printed and counterprinted impressions; (2'))providing a metallic plate having its face sensitized with a materialwhich is normally soluble in water but which can be rendered insolublein water by exposure to light; (0) applying said master sheet facedownward to the face of said metallic plate and subjecting the same to astrong light; (03) washing said plate with water to remove thesensitizing material from the surfaces of the said plate which had beencovered by said opaque impressions of the master sheet, thereby leavingsaid surfaces exposed; (e) then covering said exposed surfaces withprinters ink; then swabbing said plate with a dilute solution ofhydrochloric acid to remove the sensitizing material from the surfacesof said plate which had not been covered by the opaque impressions ofthe master sheet; and (g) subjecting said plate to the etching action ofan electrolytic bath for etching off those surfaces of said plate whichhad not been covered by the opaque impressions of said master sheet,thereby leaving the surfaces of said plate which had been covered by theopaque impressions of said master sheet standing high and distinct, inrelief, and thus affording a negative printing plate available forprinting right side up.

3. As a step in a process for producing printing plates having type inhigh relief, the production of a translucent master sheet containing thedesired composition typewritten in opaque printed and counterprintedimpressions, reading right side up on the face of the sheet and reversedon the back of the sheet.

4. The process of producing printing plates having type in high relief,which process includes the following steps, to-wit :(a) producing atranslucent master sheet containing the desired composition intypewritten opaque printed and counter-printed impressions; (6)providing a metallic plate having its face sensitized with a materialwhich is normally soluble in water but which can be rendered insolublein water by exposure to light, (a) applying said master sheet, facedownward, to the sensitized face of said metallic plate and subjectingthe same to a strong light; ((2) removing the sensitizing material fromthe surfaces of said plate which had been covered by the opaqueimpressions of said master sheet leaving said surfaces exposed; (6)covering said exposed surfaces with a material which will resist thenext two steps of subsequent treatment; (7) removing the sensitizingmaterial from the surfaces of said plate which had not been covered bythe opaque impressions of said master sheet; (g) etching off from saidplate all the face surfaces thereof not corresponding to saidcomposition of said master sheet.

5. The. process of producing printing plates having type in high relief,which process includes the following steps, to-wit: (a) producing atranslucent master sheet containing the desired composition intypewritten opaque impressions; (6) providing a metallic plate havingits face sensitized with a material which is normally soluble in aliquid but which can be rendered insoluble in said liquid by exposure tolight; (0) applying said master sheet, face downward, to the sensitizedface of said metallic plate and subjecting the same to a strong light;(65) removing the sensitizing material from the surfaces of saidplate'which had been covered by the opaque impressions of said mastersheet, leaving said surfaces exposed; (e) covering said exposed surfaceswith a material which will resist the next two steps of subsequenttreatment; (f) removing the sensitizing material from the surfaces ofsaid plate which had not been covered by the opaque impressions of saidmaster sheet; (g) etching off fromsaid plate all the face surfacesthereof not corresponding to said composition of said master sheet.

6. The process of producing printing plates having type in high relief,which process includes the following steps, to wit (a) producing atranslucent master sheet having the desired composition thereon intypewritten opaque'impressions, leaving the remaining portions of saidsheet translucent; (b) transferring the composition of the master sheetto a metallic printing plate; (0) etching off from the face of saidmetallic printing plate all the face surfaces thereof not correspondingto said composition of said

